Unfortunately, only people who own a Kindle can buy ebooks from the Amazon Kindle site. If you are looking for free classics this forum has a great collection -- if you haven't found them yet, go to the top of the page and click on the 'ebooks' tab, use the Sony format. You can also download free classics from Feedbooks and Manybooks.

Does anyone know of a way a Brit with a Sony ereader can take advantage of this, please??? I have not been able to figure out how to use Amazon for anything except the Kindle... Thanks so much!

All of the those ebooks are also on Mobipocket.com. True, they are in Mobipocket format, but that is not a major problem. Calibre can accept that format as an input, and output the ebooks for your Sony Reader.

There is once again hope of finding the featured/promotional books for the Kindle, in the sea of public domain books! This search sorts them so that the featured books are listed first (it also appears to show any free blogs, so I suspect it will show free magazine or newspaper issues, if they exist):

The first one I set up limits the list to free (zero dollar) Kindle books and sorts by "promotions/features". The second link also excludes the publisher "public domain books" and right now gives you just 12 books (the current freebies). Hopefully in a few days those 16 Harlequin books will join the list.